title: Effective activity of cytokine-induced killer cells against autologous metastatic melanoma including cells with stemness features.
abstract: OBJECTIVE
  We investigate the unknown tumor-killing activity of cytokine-induced killer (CIK) cells against autologous metastatic melanoma and the elusive subset of putative cancer stem cells (mCSC).
  
  
  METHODS
  We developed a preclinical autologous model using same patient-generated CIK cells and tumor targets to consider the unique biology of each patient/tumor pairing. In primary tumor cell cultures, we visualized and immunophenotypically defined a putative mCSC subset using a novel gene transfer strategy that exploited their exclusive ability to activate the promoter of stemness gene Oct4.
  
  
  RESULTS
  The CIK cells from 10 patients with metastatic melanoma were successfully expanded (median, 23-fold; range, 11-117). Primary tumor cell cultures established and characterized from the same patients were used as autologous targets. Patient-derived CIK cells efficiently killed autologous metastatic melanoma [up to 71% specific killing (n = 26)]. CIK cells were active in vivo against autologous melanoma, resulting in delayed tumor growth, increased necrotic areas, and lymphocyte infiltration at tumor sites. The metastatic melanoma cultures presented an average of 11.5% ± 2.5% putative mCSCs, which was assessed by Oct4 promoter activity and stemness marker expression (Oct4, ABCG2, ALDH, MITF). Expression was confirmed on mCSC target molecules recognized by CIK cells (MIC A/B; ULBPs). CIK tumor killing activity against mCSCs was intense (up to 71%, n = 4) and comparable with results reported against differentiated metastatic melanoma cells (P = 0.8).
  
  
  CONCLUSIONS
  For the first time, the intense killing activity of CIK cells against autologous metastatic melanoma, including mCSCs, has been shown. These findings move clinical investigation of a new immunotherapy for metastatic melanoma, including mCSCs, closer.
authors.affiliation: Unit of Stem Cell Transplantation and Cell Therapy, Surgical Dermatology, Pathology, and Sarcoma, Fondazione del Piemonte per l'Oncologia, I.R.C.C.S.,Torino, Italy.
authors.forename: Loretta
authors.initials: L
authors.lastname: Gammaitoni
authors.forename: Lidia
authors.initials: L
authors.lastname: Giraudo
authors.forename: Valeria
authors.initials: V
authors.lastname: Leuci
authors.forename: Maja
authors.initials: M
authors.lastname: Todorovic
authors.forename: Giulia
authors.initials: G
authors.lastname: Mesiano
authors.forename: Franco
authors.initials: F
authors.lastname: Picciotto
authors.forename: Alberto
authors.initials: A
authors.lastname: Pisacane
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zaccagna
authors.forename: Maria Giuseppa
authors.initials: MG
authors.lastname: Volpe
authors.forename: Susanna
authors.initials: S
authors.lastname: Gallo
authors.forename: Daniela
authors.initials: D
authors.lastname: Caravelli
authors.forename: Elena
authors.initials: E
authors.lastname: Giacone
authors.forename: Tiziana
authors.initials: T
authors.lastname: Venesio
authors.forename: Antonella
authors.initials: A
authors.lastname: Balsamo
authors.forename: Ymera
authors.initials: Y
authors.lastname: Pignochino
authors.forename: Giovanni
authors.initials: G
authors.lastname: Grignani
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Carnevale-Schianca
authors.forename: Massimo
authors.initials: M
authors.lastname: Aglietta
authors.forename: Dario
authors.initials: D
authors.lastname: Sangiolo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055612:Cytokine-Induced Killer Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D016219:Immunotherapy, Adoptive; D008297:Male; D008545:Melanoma / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D008875:Middle Aged; D009362:Neoplasm Metastasis; D014411:Neoplastic Stem Cells / Q000276:immunology* / Q000378:metabolism; D010641:Phenotype; D061251:Primary Cell Culture; D014407:Tumor Cells, Cultured